The present invention relates to an absorbent article such as a disposable diaper offering nice fit, and comfort while worn and enhanced leakage preventive property.
1. Field of the Invention
There has heretofore been known a disposable diaper in which a leg region elastic member for forming leg gathers is disposed across an under-crotch region from one of the two leg regions, which are disposed around wearer""s legs, to the other one, and the leg region elastic member is cut off at the under-crotch region.
2. Description of Background Art
In such a disposable diaper, a thready rubber is used as the leg region elastic member, which is small in elongation stress, excellent in adhesive property with respect to a sheet material such as a nonwoven fabric for sandwichingly holding the thready rubber. The reason why such a material is used as the leg region elastic member is as follows. If an elastic member having a large elongation stress such as a thick thread-like rubber or an elastic member with a talc stuck to its outer surface and therefore having a poor adhesive property such as a natural rubber should be used as a leg region elastic member, so-called xe2x80x9crubber removalxe2x80x9d would occur, wherein the cutting-off of the leg region elastic member at the under-crotch region causes spread of a released condition of the elongated state of the elastic member over to the side edges of the leg region during the time of manufacture or during the time of wearing such a disposable diaper. As a result, there is such a fear that the fitness around the leg is deteriorated to thereby allow generation of leakage.
However, if an elastic member having a small elongation stress should be used as a leg region elastic member, leakage of urine and feces might occur because its tightening strength around the leg region is insufficient and so the elastic member cannot follow the active motion of the wearer. If an elastic member having a small elongation stress should be arranged at a high elongation ratio in order to solve such a problem as just mentioned, the adhesive property with respect to a sheet such as a nonwoven fabric for sandwichingly holding the elastic member would be lowered.
If the adhesive agent for fixing the elastic member should be increased in quantity in order to prevent the occurrence of rubber removal, flexibility would be lowered due to the increased quantity of adhesive agent and the elongation physical property of the elastic member would be deteriorated to lower the fitness and moreover, physical irritation to the wearer""s skin would be resulted. In addition, the adhesive agent would be oozed out from the sheet such as a nonwoven fabric for sandwichingly holding the elastic member. Consequently, the wearer may have an unpleasant feel because of stickiness and diaper rash may be resulted.
Japanese Patent Application Laid-Open Publication Nos. S57-77304 and S57-117602 disclose absorbent articles in which a leg region elastic member is cut off at an under-crotch region. However, those publications do not teach at all a method for obtaining a proper tightening strength around the leg while preventing the occurrence of rubber removal caused by the cutting-off of the leg region elastic member at the under-crotch region.
It is an object of the present invention to provide an absorbent article such as a disposable diaper, in which an elongation stress of an elastic member for forming leg gathers and an arrangement elongation ratio thereof can be determined relatively freely during the time for development of products so that a proper tightening strength around the leg can be obtained and in which fitness and absorption performance can be improved without accompanying with any inconvenience such as deterioration in flexibility around the leg, irritation to the wearer""s skin or the like, and a method for manufacturing a laminated sheet capable of efficiently manufacturing a laminated sheet suited to be used for manufacturing such an absorbent article.
Another object of the present invention is to provide an absorbent article, in which so-called rubber removal does not occur at the time of manufacture and at the time of wearing such an absorbent article, in which excellent fitness and absorption performance can be obtained, and in which a concave pocket structure is surely formed in the under-crotch region to thereby enable to obtain an excellent anti-leakage property.
The present invention has achieved the above objects by providing an absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable anti-leakage sheet and a liquid-retentive absorbent core interposed between the topsheet and the anti-leakage sheet, a leg region elastic member for forming leg gathers being arranged in an elongated state thereof at a leg region arranged around a wearer""s leg, wherein the leg region elastic member comprises a first and a second elastic member, and the first and second elastic members each include a pair of gather forming parts arranged at a pair of the leg regions and a traversing part arranged in such a manner as to traverse the absorbent core, gather forming parts of the first and second elastic members at each leg region being arranged such that the gather forming parts are oriented in opposite directions with each other, the gather forming parts of the first and second elastic members are fixed to a component of the absorbent article by a first fixing means, and the first and/or second elastic members do not exhibit elastic expansible/contractible property at least at a widthwise central area of that part of the traversing part where the absorbent core exists, and a predetermined part of the first and/or second elastic member including a portion which does not exhibit elastic expansible/contractible property is fixed to the component of the absorbent article by a second fixing means (the expression xe2x80x9cthe first inventionxe2x80x9d used hereinafter refers to this invention).
Moreover, the present invention has achieved the above objects by providing a shorts-type absorbent article comprising a liquid-permeable topsheet, a liquid-impermeable anti-leakage sheet and a liquid-retentive absorbent core interposed between the topsheet and the anti-leakage sheet, a leg region elastic member for forming leg gathers arranged in an elongated state at a leg region arranged around a wearer""s leg, wherein the leg region elastic member comprises a first and a second elastic member, and the first and second elastic members each include a pair of gather forming parts arranged at a pair of the leg regions and an extension part extending from the gather forming parts towards a widthwise central area of the absorbent article, the gather forming parts of the first and second elastic members are fixed to a component of the absorbent article by a first fixing means, the extension part of the first and/or second elastic member is fixed to the component of the absorbent article by a second fixing means at a part where the absorbent core exists, and at least a portion of the extension part located at the part where the absorbent core exists exhibits elastic expansible/contractible property, and the first and second elastic members do not exhibit elastic expansible/contractible property at least at a widthwise central area of the part where the absorbent core exists (the expression xe2x80x9cthe second invention used hereinafter refers to this invention).
Moreover, the present invention has achieved the above objects by providing a method for manufacturing a partly elasticized laminated sheet comprising the steps of applying an adhesive agent as first fixing means to at least one of two consecutive sheets which are stuck to each other in a predetermined pattern, sticking the two consecutive sheets together after the elastic member is introduced while oscillating the elastic member in a direction orthogonal to a flowing direction of the two consecutive sheets so that the elastic member is fixed between the two consecutive sheets through the adhesive agent, dividing the elastic member at a predetermined part, and fixing the predetermined part of the elastic member to at least one of the two consecutive sheets by second fixing means before or after, or at the same time the elastic member is divided (the expression xe2x80x9cthe third inventionxe2x80x9d used hereinafter refers to this invention).
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.